Windows Update Error 80240016

I'm running Vista Home Premium.

After updating to SP1, I got a message for the cumulative update: Media Center for Windows Vista (KB955519).

Every time I try to download it, it fails. Unable to download or install, with error 80240016. I haven't been able to get past this or get any further updates since this problem started. Every time I boot I get the error msg that it's unable to check for updates.

Any help with this matter would be appreciated.